What is the role of dynamic cervical spine radiographs in predicting pseudarthrosis revision following anterior cervical discectomy and fusion?

Background ContextPostoperative dynamic radiographs are used to assess fusion status after anterior cervical discectomy and fusion (ACDF) with comparable accuracy to computed tomography (CT) scans.PurposeTo (1) determine if dynamic radiographs accurately predict pseudarthrosis revision in a cohort of largely asymptomatic patients who underwent ACDF, (2) determine how adjacent segment motion is affected by fusion status, and (3) analyze how clinical outcomes differ between patients with symptomatic and asymptomatic pseudarthrosis.Study DesignRetrospective cohort study.Patient SamplePatients ≥ 18 years who underwent primary one- to four-level ACDF at a single institution over a 10-year period.Outcome MeasuresInterspinous motion on preoperative and postoperative flexion-extension radiographs and preoperative and postoperative Visual Analogue Scale for Neck Pain (VAS Neck) and Arm Pain (VAS Arm), Neck Disability Index (NDI), Modified Japanese Orthopaedic Association scale (mJOA), Mental and Physical Component Scores of the Short-Form 12 (SF-12) Health Survey (MCS-12 and PCS-12)MethodsThe difference in spinous process motion between flexion and extension radiographs was used to determine motion at each level of the ACDF construct. Pseudarthrosis was defined as ≥ 1 mm spinous process motion on dynamic radiographs. A receiver operating characteristic (ROC) curve was generated to predict the probability of surgical revision for pseudarthrosis based on millimeters of interspinous motion at each instrumented level. Patient reported outcome measures (PROMs) were used to assess the effect of pseudarthrosis on clinical outcomes. Alpha was set at p<.05.ResultsA total of 597 patients met inclusion criteria including 1,203 ACDF levels. Of those, 215 patients (36.0%) were diagnosed with a pseudarthrosis on dynamic radiographs with 29 patients (4.9%) requiring pseudarthrosis revision. ROC analysis identified a “cutoff” value of 1.00 mm of interspinous process motion for generating an optimal area under the curve (AUC). The negative predictive value (NPV) was 99.6%, whereas the positive predictive value (PPV) was 13.7%. When analyzing adjacent segment motion, the Δ supra-adjacent interspinous process motion (ISM) was significantly lower for patients with a superior construct pseudarthrosis (-1.06 mm vs. 1.80 mm, p<.001), whereas the Δ infra-adjacent level ISM was significantly lower for patients with an inferior construct pseudarthrosis (-1.21 mm vs. 2.15 mm, p<.001). Patients with a pseudarthrosis not requiring revision had worse postoperative NDI (29.3 vs. 23.4, p=.027), VAS Neck (3.40 vs. 2.63, p=.012), and VAS Arm (3.09 vs. 1.85, p=.001) scores at 3 months, but not 1-year, compared with patients who were fused. Patients requiring pseudarthrosis revision had higher 1-year postoperative NDI (38.0 vs. 23.7, p=.047) and lower 1-year postoperative Δ VAS Arm (-0.22 vs. -2.97, p=.016) scores.ConclusionsOne-year postoperative dynamic radiographs have a greater than 99% negative predictive value for identifying patients requiring pseudarthrosis revision, but they have a low positive predictive value. Most patients with a pseudarthrosis remain asymptomatic with similar 1-year postoperative patient-reported outcomes compared with patients without a pseudarthrosis.     

How do C2 tilt and C2 slope correlate with patient reported outcomes in patients after anterior cervical discectomy and fusion?

BACKGROUND/CONTEXTC2 tilt and C2 slope are quick and easy measurements to obtain on lateral radiographs and may be used to determine overall cervical sagittal alignment; however, the influence of these measurements on patient outcomes has not been well established in literature.PURPOSETo determine if C2 tilt and/or C2 slope predict patient outcomes better compared with conventional radiographic measures after an anterior cervical discectomy and fusion (ACDF).STUDY DESIGN/SETTINGRetrospective cohort study.PATIENT SAMPLEA total of 249 patients who underwent 1 to 3 level ACDF to address radiculopathy and/or myelopathy at a single academic institution between 2011 and 2015 were identified. Patients with less than 1 year of follow-up were excluded.OUTCOME MEASURESPatient Reported Outcomes: Neck Disability Index (NDI), Physical Component Score-12 (PCS-12), and Mental Component Score (MCS-12), Visual Analog Score (VAS) Neck and Arm scoresCervical radiographic measurements: C2 tilt, C2 slope, C2–C7 lordosis, cervical SVA, T1 slope, T1 slope minus cervical lordosis (TS-CL), and C2–C7 ROMMETHODSPearson correlation tests were performed to assess for significant associations between radiographic measurements and patient outcomes. Multiple linear regression models were developed adjusting for demographics and radiographic parameters to determine which factors were predictive of patient outcomes.RESULTSC2 tilt and TS-CL correlated with all postoperative physical outcome scores (NDI, PCS-12, VAS Neck and ARM; p<.05), however no association was seen between C2 slope and postoperative outcomes. After accounting for the presence of subaxial deformity, C2 tilt and TS-CL remained strongly correlated to patient outcome scores. With multiple linear regression, C2 tilt was a significant predictor for NDI, whereas TS-CL was a significant predictor for PCS-12, VAS Neck and VAS Arm.CONCLUSIONSC2 tilt significantly correlated with well-described conventional cervical parameters as well as postoperative physical outcomes measures, especially NDI, on multivariate analysis. C2 tilt may provide an easy and practical tool for predicting physical outcomes after ACDF.     

Cervical kinematics and radiological changes after Discover artificial disc replacement versus fusion

Background contextThe cervical disc arthroplasty has emerged as a promising alternative to the anterior cervical discectomy and fusion (ACDF) in patients with radiculopathy or myelopathy with disc degeneration disease. The advantages of this technique have been reported to preserve the cervical mobility and possibly reduce the adjacent segment degeneration. However, no studies have compared the clinical outcomes and radiological results in patients treated with Discover artificial disc replacement to those observed in matched group of patients that have undergone ACDF.PurposeWe conducted this clinical study to compare the cervical kinematics and radiographic adjacent-level changes after Discover artificial disc replacement with ACDF.Study designAnalysis and evaluation of data acquired in a comparative clinical study.Patient sampleThe number of patients in the Discover and ACDF group were 149 and 196, respectively.Outcome measuresThe Neck Disability Index (NDI) and visual analog scale (VAS) pain score were evaluated. The range of movement (ROM) by the shell angle, the functional segment unit and global angles were measured, and the postoperative radiological changes at adjacents levels were observed.MethodsA total of 149 patients with symptomatic single or two-level cervical degenerative diseases received the Discover cervical artificial disc replacement from November 2008 to February 2010. During the same period, there were a total of 196 patients undergoing one or two-level ACDF. The average follow-up periods of the Discover disc group and ACDF group were 22.1 months and 22.5 months, respectively. Before surgery, patients were evaluated using static and dynamic cervical spine radiographs in addition to computerized tomography and magnetic resonance imaging. Static and dynamic cervical spine radiographs were obtained after surgery and then at 3- and 6-month follow-up. Then, the subsequent follow-up examinations were performed at every 6-month interval. The clinical results in terms of NDI and VAS scores, the parameters of cervical kinematics, postoperative radiological changes at adjacent levels, and complications in the two groups were statistically analyzed and compared. No funding was received for this study, and the authors report no potential conflict of interest–associated biases in the text.ResultsAlthough the clinical improvements in terms of NDI and VAS scores were achieved in both the Discover and ACDF group, no significant difference was found between the two groups for both single- (VAS p=.13, NDI p=.49) and double-level surgeries (VAS p=.28, NDI p=.21). Significant differences of cervcial kinematics occurred between the Discover and the ACDF group for both the single- and double-level surgeries at the operative segments (p<.001). Except the upper adjacent levels for the single-level Discover and ACDF groups (p=.33), significant increases in adjacent segment motion were observed in the ACDF group compared with the minimal ROM changes in adjacent segment motion noted in the Discover group, and the differences between the two groups for both single and double-level procedures were statistically significant (p<.05). There were significant differences in the postoperative radiological changes at adjacent levels between the Discover and ACDF groups for the single-level surgery (p<.001, χ²=18.18) and the double-level surgery (p=.007, χ²=7.2). No significant difference of complications was found between the Discover and ACDF groups in both single (p=.25, χ²=1.32) and double-level cases (p=.4, χ²=0.69).ConclusionsThe adjacent segment ROM and the incidence of radiographic adjacent-level changes in patients undergoing ACDF were higher than those undergoing Discover artificial disc replacement. The cervical mobility was relatively well maintained in the Discover group compared with the ACDF group, and the Discover cervical disc arthroplasty can be an effective alternative to the fusion technique.     

Impact of preoperative weakness and duration of symptoms on health-related quality-of-life outcomes following anterior cervical discectomy and fusion

BACKGROUND CONTEXTThe majority of patients with preoperative upper extremity weakness show improvements in motor function after anterior cervical discectomy and fusion (ACDF). Although numerous studies have examined both the extent and time course to which motor function can be expected to improve, few have shown that these improvements in motor function translate to improved health related quality of life (HRQOL) outcomes.PURPOSEThe purpose of this study was to examine the effect of preoperative weakness and duration of symptoms on HRQOL outcomes in patients who underwent ACDF.STUDY DESIGNRetrospective cohort study.PATIENT SAMPLEAdult patients who underwent an ACDF procedure at an academic hospital from January 2015 to December 2016 by a fellowship-trained spine surgeon.OUTCOME MEASURESThe primary outcomes of interest were HRQOL outcomes: Short Form-12 Physical/Mental Component Scores (SF-12 PCS/MCS), Neck Disability Index (NDI), and Visual Analog Scale Arm/Neck scores (VAS Arm/Neck).METHODSPatient demographics, surgical case characteristics, and motor strength exams were collected in patients who underwent ACDF over a 2-year period. Preoperative weakness was defined by a strength grade ≤3 (on a scale from 0 to 5) in at least one upper extremity muscle group. Multivariate linear regression analysis was performed to determine the effect of the preoperative weakness on HRQOL outcomes.RESULTSOf the 276 patients identified, 45 (16.3%) showed evidence of preoperative weakness, 44 (97.8%) of which showed subsequent postoperative motor improvements after ACDF. All patients reported significant improvements in all HRQOL outcome measures. Patients with preoperative weakness reported significantly worse preoperative VAS Arm (6.9 vs. 5.2; p=.01) and VAS Neck (6.1 vs. 4.8; p=.02) pain scores. Compared with patients without preoperative weakness, those with preoperative weakness reported significantly more improvement in NDI (β: −10.9; p=.001). Patients with symptoms greater than or equal to 12 months and preoperative weakness showed significantly less improvement in NDI (β: 14.8; p=.03).CONCLUSIONSPatients with preoperative weakness generally exhibited worse pain and HRQOL measures preoperatively, and showed greater potential for improvement after ACDF. Patients with a shorter duration of preoperative weakness had greater potential for improvement in HRQOL measures after ACDF compared with those with longer duration of symptoms. ACDF is an effective procedure to improve strength and HRQOL measures across all patient groups under appropriate indications.     

Impact of age within younger populations on outcomes following cervical surgery in the ambulatory setting

ObjectiveTo determine the effect of age within the younger population seen at ambulatory surgical centers on patient-reported outcome measures (PROMs) after cervical spine surgery.MethodsPatients of age <65 years undergoing single-level anterior cervical discectomy and fusion (ACDF) or cervical disc replacement (CDR) were included. Patients were divided by mean age of initial population (46 years). PROMs included Patient-reported Outcome Measurement Information System Physical Function (PROMIS-PF), 12-Item Short-Form Physical Component Survey (SF-12 PCS), Visual Analog Scale (VAS) neck, VAS arm, Neck Disability Index (NDI) collected preoperatively and at postoperative time points up to 2 years.Results138 patients were included, with 66 patients <46 years. Both cohorts demonstrated improvement from preoperative baseline with regard to all studied PROMs at multiple time points postoperatively (p ≤ 0.042, all). Between groups, the older cohort demonstrated greater mean PROMIS-PF scores preoperatively and at 6 weeks (p ≤ 0.011, both), while VAS arm scores were lower in the older group at 1 year (p = 0.002), and NDI scores were lower in the older group at 6 weeks and 1 year (p < 0.027, both). Minimal Clinically Important Difference (MCID) achievement rates were greater in the younger group in PROMIS PF at 2 years (p = 0.002), and in the older group in VAS arm score at 1 year (p = 0.007).ConclusionBoth cohorts showed significant improvement at multiple postoperative time points for all PROMs. Between groups, the older group reported more favorable physical function, VAS arm, and NDI scores at several time points. However, MCID achievement rates only significantly differed in two PROMs at singular time points. Difference in age in patients <65 years likely does not significantly affect long-term outcomes after cervical spine surgery.     

Revision lumbar fusions have higher rates of reoperation and result in worse clinical outcomes compared to primary lumbar fusions

BACKGROUND CONTEXTIndications for revision lumbar fusion are variable, but include recurrent stenosis (RS), adjacent segment disease (ASD), and pseudarthrosis. The efficacy of revision lumbar fusion has been well established, but their outcomes compared to primary procedures is not well documented.PURPOSEThe purpose of this study was to compares surgical and clinical outcomes between (1) revision and primary lumbar fusion, (2) revision lumbar fusion based on indication (ASD, pseudarthrosis, or RS), and (3) revision lumbar fusion based on whether the index procedure included an isolated decompression or decompression with fusion.STUDY DESIGN/SETTINGRetrospective single-institution cohort study.PATIENT SAMPLEFour thousand six hundred seventy-one consecutive lumbar fusions from 2011 to 2021, of which 892 (23.6%) were revision procedures. The indication for revision procedures included 502 (56.3%) for ASD, 153 (17.2%) for pseudarthrosis, and 237 (26.6%) for RS. Of the 892 revision procedures, 694 (77.8%) underwent an index fusion while 198 (22.2%) underwent an index decompression without fusion.OUTCOME MEASURESHospital readmissions, all-cause reoperation, need for subsequent revision and patient reported outcome measures (PROMs) at baseline, 3-months postoperatively, and 1-year postoperatively, including the Mental Health Component score (MCS-12) and Physical Health Component score (PCS-12) of the Short Form 12 survey, the Oswestry Disability Index (ODI), and the Visual Analog Scale (VAS) for Back and Leg pain.METHODSPatient demographics, comorbidities, surgical characteristics, and outcomes were collected from electronic medical records. Twenty-eight percent of patients had preoperative and postoperative PROMs. A delta PROM score was calculated for the 3-month and 1-year postoperative timepoints, which was the change from the preoperative to postoperative value. Univariate comparisons were performed to compare revision fusions to primary fusions. Multivariate logistic regression was performed for all-cause reoperation and subsequent revision surgery, while multivariate linear regression was performed for ?PROMs at 3-months and 1-year. Revision procedures were then separately regrouped based on indication for revision fusion and whether they underwent a fusion for their index procedure. Univariate comparisons and multivariate linear regressions for ?PROMs were then repeated based on the new groupings.RESULTSThere was no difference in hospital readmission rate (5.38% vs. 4.60%, p=.372) or length of stay (4.10 days vs. 3.94 days, p=.129) between revision and primary lumbar fusion, but revision fusions had a higher rate of all-cause reoperation (16.1% vs. 11.2%, p<.001) and subsequent revision (13.7% vs. 9.71%, p=.001), which was confirmed on multivariate logistic regression (Odds Ratio (OR): 1.42, p=.001 and OR: 1.37, p=.007, respectively). On multivariate analysis, a revision procedure was an independent risk factor for worse improvement ?ODI, ?VAS Back, ?VAS Leg, and ?PCS-12 and 1-year postoperatively. Regardless of the indication for revision lumbar fusion, patients significantly improved in the 3-month and 1-year postoperative PCS-12, ODI, VAS Back, and VAS Leg, with the exception of the 3-month PCS-12 for pseudarthrosis (p=.620). Patients undergoing revision for ASD had significantly worse 1-year postoperative PCS-12 (32.3 vs. Pseudarthrosis: 35.6 and RS: 37.0, p=.026), but there were no differences in ?PROMs. There was no difference in hospital readmission, all-cause reoperation, or subsequent revision based on whether a patient had an index lumbar fusion or isolated decompression. Multivariate linear regression analysis found that a surgical indication of pseudarthrosis was a significant predictor of decreased improvement in 3-month ?VAS Leg (ref: ASD, β=2.26, p=.036), but having an index fusion did not significantly predict worse improvement in ?PROMs when compared to isolated decompressions.CONCLUSIONSRevision lumbar fusions had a higher rate of reoperation and subsequent revision surgery when compared to primary lumbar fusions, but there were no difference in hospital readmission rates. Patients undergoing revision lumbar fusion experience improvements in all patient reported outcome measures, but their baseline, postoperative, and magnitude of improvement are worse than primary procedures. Regardless of whether the lumbar fusion is a primary or revision procedure, all patients have significant improvements in pain, disability and physical function. Further, the indication for the revision procedure is not correlated with the expected magnitude of improvement in patient reported outcomes. Finally, no differences in baseline, postoperative, and ?PROMs for revision fusions were identified when stratifying by whether the patient had an index decompression or fusion.     

Workers compensation patients experiencing depression report meaningful improvement in mental health scores after anterior cervical discectomy and fusion

BackgroundMental health has been demonstrated to affect postoperative outcomes. No prior literature has reported the relationship between preoperative mental health on outcomes following anterior cervical discectomy and fusion (ACDF) in the Workers Compensation (WC) population.MethodsWC claimants who underwent primary ACDF were identified from a single-surgeon retrospective database. Patients were separated by SF-12 MCS score into Depressed (<45.6) or Not Depressed (ND) (≥45.6) cohorts. Patient-reported Outcome Measurement Information System Physical Function (PROMIS PF), SF-12 Physical Component Score (SF-12 PCS), SF-12 MCS, visual analog scale (VAS) neck/arm pain, and Neck Disability Index (NDI) were collected and compared within and between groups. Minimum clinically important difference (MCID) achievement rates were compared between groups.ResultsDepressed patients had greater length of stay (p = 0.007) and postoperative narcotic consumption (p = 0.026). Depressed patients improved at 12-week to 2-year PROMIS PF, 6-month SF-12 PCS, 6-week to 6-month SF-12 MCS, 6-week to 6-month and 2-year VAS neck, all VAS arm, and 6-month NDI (p ≤ 0.045, all). ND patients improved at 12-week to 1-year PROMIS PF, 6-month to 2-year SF-12 PCS, 12-week to 1-year VAS neck, 6-week to 1-year VAS arm, and 12-week to 1-year NDI (p ≤ 0.044, all). Between groups, ND patients reported superior PROMIS PF, SF-12 MCS, VAS neck, VAS arm, and NDI scores at two or more periods (p ≤ 0.045, all). MCID achievement rate regarding SF-12 MCS was greater in the Depressed cohort at all postoperative points up to 1 year (p ≤ 0.020, all).ConclusionDepressed patients tended to have a greater length of stay and postoperative narcotic consumption immediately after surgery. Not depressed patients reported more favorable physical and mental function, pain, and disability scores preoperatively and postoperatively. Depressed patients reported greater MCID achievement in mental function following surgery. Depressed patients with WC have a greater likelihood of reporting tangible improvement in mental health scores following ACDF.     

How do spinopelvic parameters influence patient-reported outcome measurements after lumbar decompression?

BACKGROUND CONTEXTSpinopelvic parameters indicative of sagittal imbalance include a pelvic tilt (PT) greater than 20° and a mismatch between pelvic incidence (PI) and lumbar lordosis (LL) greater than 10°. However, unlike in fusion surgery, the relationship between spinopelvic parameters and patient-reported outcome measurements (PROMs) in patients undergoing lumbar decompression surgery for neurologic symptoms is less clear.PURPOSETo determine whether PROMs are affected by the amount of residual (postoperative) PI-LL mismatch or PT in patients undergoing one- to three-level lumbar decompression surgeries.DESIGNRetrospective cohort study (Level of Evidence: III).PATIENT SAMPLEPatients undergoing between one to three levels of lumbar decompression surgery at a single, academic institution.OUTCOME MEASURESPROMs—including the PCS-12, MCS-12, ODI, and VAS Back and Leg pain scores—and radiographic measurements of spinopelvic parameters.METHODSPatients were separated into groups based on a postoperative PI-LL mismatch of ≤10° or >10° and a postoperative PT<20° or ≥20°. Absolute PROM scores, the recovery ratio (RR) and the percentage of patients achieving Minimum Clinically Important Difference between groups were compared and a multiple linear regression analysis was performed.RESULTSA total of 167 patients were included, with 27 patients in the PI-LL>10° group and 91 patients in the PT≥20° group. All groups exhibited significant improvement after surgery for each PROM included (p<.05) except for MCS-12 scores in the PI-LL≤10° group and both PT groups. Comparing between groups, all patients were similar with respect to preoperative scores, postoperative scores, change in scores, recovery ratios, and percentage change in Minimum Clinically Important Difference, except that patients with PT≥20° had higher pre- and postoperative VAS Back scores (p=.036 and p=.024, respectively). With multiple linear regression, postoperative PI-LL>10° and PT≥20° were not significant predictors of worse outcomes for any measured PROM.CONCLUSIONSPatients with postoperative measurements PI-LL>10° and PT≥20° without instability had similar PROMs at 1 year after limited lumbar decompression when compared to patients without a spinopelvic mismatch.     

Which NDI domains best predict change in physical function in patients undergoing cervical spine surgery?

Background ContextPhysical function is a critical aspect of patient outcomes. NDI is a widely validated outcome measure in cervical spine disease, yet to what extent its individual domains predict changes in physical function remains unknown.PurposeTo examine the impact of individual NDI domains on changes in physical function in patients undergoing cervical spine surgery.Study Design/SettingProspective Cohort Study.Patient SampleAdult patients undergoing cervical spine surgery, excluding those undergoing surgery for instability due to trauma.Outcome MeasuresAbsolute change in outcome measures (Patient Reported Outcomes Measurement Information System [PROMIS] Physical Function [PF], Short Form 36 [SF-36] Physical Component Score [PCS], and Neck Disability Index [NDI]) from pre- to postoperatively, correlation of NDI individual domains with PROMIS PF and SF-36 PCS (preoperatively, postoperatively, and change from pre- to postoperatively).MethodsPatients undergoing cervical spine surgery between 2016 and 2018 were prospectively enrolled. Patients completed questionnaires (NDI, SF-36 PCS, and PROMIS PF) preoperatively and at 6 months postoperatively. Patient demographics, including age, body mass index, Charlson Comorbidity Index, and underlying diagnoses were collected. Comparisons between NDI scores preoperatively versus postoperatively were conducted using Wilcoxon signed rank sum test. Correlations of NDI individual items and PROMIS/SF-36 were assessed using Pearson correlation. A stepwise linear regression analysis was performed to identify NDI items that are independently predictive of PROMIS PF and SF-36 PCS.ResultsA total of 137 patients were included in the study, with mean age 56.9 years (range 24.4–84.9). Each of the NDI domains as well as PROMIS PF and SF-36 PCS demonstrated significant improvement following cervical spine surgery (p<.001). Changes in all NDI domains demonstrated significant negative correlation with changes in PROMIS PF, with recreation (R=−0.537, p<.001), work (R=−0.514, p<.001), and pain intensity (R=−0.488, p<.001) having the greatest negative correlation. Changes in all NDI domains demonstrated significant negative correlation with changes in SF-36 PCS, with recreation (R=−0.451, p<.001), work (R=−0.443, p<.001), lifting (R=−0.373, p<.001), and driving (R=−0.373, p<.001) having the greatest negative correlation. For PROMIS PF, the NDI domains that were independently associated with changes in PF were work (R=−0.092, p=.001), pain intensity (R=−0.089, p=.003), and recreation (R=−0.067, p=.004). For SF-36 PCS, the NDI items that were independently associated with changes in PCS were work (R=−0.269, p=.003) and recreation (R=−0.215, p=.002).ConclusionsAll NDI domains improve significantly after cervical spine surgery and demonstrate significant correlation with changes in PROMIS PF and SF-36 PCS. The work, recreation, and pain intensity domains were the only independent predictors of physical function changes postoperatively. Considering physical function, our findings highlight the importance of presenting changes in individual NDI domains in addition to the total score.     

Validating the VR-12 Physical Function Instrument After Anterior Cervical Discectomy and Fusion with SF-12, PROMIS,and NDI

Background

Development and validation of Veterans RAND 12-item (VR-12) physical component survey (PCS) has been established among civilian and veteran populations but it has not been examined among anterior cervical discectomy and fusion (ACDF) patients.

Purposes/Questions

We sought to validate legacy patient-reported outcome measures (PROMs) with VR-12 PCS among patients undergoing ACDF procedures.

Methods

A prospectively collected surgical registry was retrospectively evaluated for elective single or multi-level ACDFs performed for degenerative spinal pathologies from January 2014 to August 2019. Exclusion criteria included missing pre-operative surveys and surgery for trauma, metastasis, or infection. Demographic variables, baseline pathologies, and peri-operative variables were collected. A paired t test evaluated the change from the pre-operative score to each post-operative timepoint for VR-12 PCS, the 12-item Short-Form Survey (SF-12) PCS, Patient-Reported Outcomes Measurement Information System physical function (PROMIS-PF), and Neck Disability Index (NDI). Minimal clinically important difference (MCID) achievement was calculated at each timepoint. Correlation was evaluated with a Pearson’s correlation coefficient and time-independent partial correlation.

Results

Of the 202 patients who underwent ACDF, 41.1% were female and the average age was 49.5 years. All PROMs had statistically significantly increased from baseline when compared with post-operative timepoints (12 weeks, 6 months, 1 year, and 2 years). MCID achievement rates increased through 2 years. All timepoints revealed strong VR-12 PCS correlations with SF-12 PCS, PROMIS-PF, and NDI scores.

Conclusion

VR-12 PCS was strongly correlated with the well-validated SF-12 PCS and NDI metrics as well as with the more recent PROMIS-PF. All PROMs demonstrated statistically significant improvement in patients post-operatively. VR-12 PCS is a valid measure of physical function among patients undergoing ACDF.

     

Poor muscle health and low preoperative ODI are independent predictors for slower achievement of MCID after minimally invasive decompression

Background ContextAlthough some previous studies have analyzed predictors of nonimprovement, most of these have focused on demographic and clinical variables and have not accounted for radiological predictors. In addition, while several studies have examined the degree of improvement after decompression, there is less data on the rate of improvement.PurposeTo identify the risk factors and predictors (both radiological and nonradiological) for slower as well as nonachievement of minimal clinically important difference (MCID) after minimally invasive decompression.DesignRetrospective cohort.Patient SamplePatients who underwent minimally invasive decompression for degenerative lumbar spine conditions and had a minimum of 1-year follow up were included. Patients with preoperative Oswestry Disability Index (ODI) <20 were excluded.Outcome MeasureMCID achievement in ODI (cut off 12.8).MethodsPatients were stratified into two groups (achieved MCID, did not achieve MCID) at two timepoints (early ≤3 months, late ≥6 months). Nonradiological (age, gender, BMI, comorbidities, anxiety, depression, number of levels operated, preoperative ODI, preoperative back pain) and radiological (MRI – Schizas grading for stenosis, dural sac cross-sectional area, Pfirrmann grading for disc degeneration, psoas cross-sectional area and Goutallier grading, facet cyst/effusion; X-ray – spondylolisthesis, lumbar lordosis, spinopelvic parameters) variables were assessed with comparative analysis to identify risk factors and with multiple regression models to identify predictors for slower achievement of MCID (MCID not achieved by ≤3 months) and nonachievement of MCID (MCID not achieved at ≥6 months).ResultsA total of 338 patients were included. At ≤3 months, patients who did not achieve MCID had significantly lower preoperative ODI (40.1 vs 48.1, p<0.001) and worse psoas Goutallier grading (p=.048). At ≥6 months, patients who did not achieve MCID had significantly lower preoperative ODI (38 vs 47.5, p<.001), higher age (68 vs 63 years, p=.007), worse average L1-S1 Pfirrmann grading (3.5 vs 3.2, p=.035), and higher rate of pre-existing spondylolisthesis at the operated level (p=.047). When these and other probable risk factors were put into a regression model, low preoperative ODI (p=.002) and poor Goutallier grading (p=.042) at the early timepoint and low preoperative ODI (p<.001) at the late timepoint came out as independent predictors for MCID nonachievement.ConclusionAfter minimally invasive decompression, low preoperative ODI and poor muscle health are risk factors and predictors for slower achievement of MCID. For nonachievement of MCID, low preoperative ODI, higher age, greater disc degeneration, and spondylolisthesis are risk factors and low preoperative ODI is the only independent predictor.     

Is the likelihood of dysphagia different in patients undergoing one-level versus two-level anterior cervical discectomy and fusion?

BACKGROUND CONTEXTDysphagia following anterior cervical discectomy and fusion (ACDF) is a common complication, the etiology of which has not been established. Given that one potential mechanism for dysphagia is local tissue edema, it is thought that a greater number of operative levels may result in higher dysphagia rates. However, prior reports comparing one-level to two-level ACDF have shown varying results.PURPOSETo determine if there is a difference in dysphagia between one-level and two-level ACDF.STUDY DESIGN/SETTINGRetrospective review of prospectively collected data.PATIENT SAMPLEPatients who underwent one- or two-level ACDF with a plate-graft construct by a single-surgeon at a high-volume academic medical center.OUTCOME MEASURESNeck Disability Index, Visual Analog Scale for neck pain and arm pain, Short Form-12 physical and mental health components, and Swallowing Quality of Life (SWAL-QOL) Questionnaire.METHODSPatient demographics, operative data, and patient-reported outcome measures (PROMs; Neck Disability Index, Visual Analog Scale, Short Form-12, and SWAL-QOL) of patients undergoing one- and two-level ACDF were compared using Fisher exact test for categorical variables and Student's t test for continuous variables. Regression analyses were conducted to identify factors associated with 6- and 12-week SWAL-QOL scores in order to determine whether the number of surgical levels impacts these outcomes.RESULTSFifty-eight patients (22 one-level and 36 two-level ACDF) were included. Patients undergoing two-level fusions were older (54.17+8.67 vs 48.06+10.68 years, p=.02) and had longer operative times (69.08+10.51 vs 53.5+14.35 minutes, p<.0001). There were no other significant differences in demographics or operative data. Both groups showed a statistically significant improvement in PROMs from preoperatively to 12 weeks. There was no difference in PROMs or dysphagia rates between groups at any time-point. Younger age (p=.023), male sex (p=.021), longer operative times (p=.068), and worse preoperative SWAL-QOL (p<.0001) were associated with dysphagia at 6 weeks. Preoperative SWAL-QOL was the only variable associated with dysphagia at 12 weeks (p=.003). Operative time of >61.5 minutes had a sensitivity and specificity of 62.1% for worse dysphagia scores at 6 weeks compared with baseline.CONCLUSIONSThe results of our study indicate that there is no difference in the degree of postoperative dysphagia in one- versus two-level ACDF. However, other variables associated with increased postoperative dysphagia in our population included younger age, male sex, procedural time >61.5 minutes, and worse preoperative dysphagia. Larger studies are required to confirm these findings and identify additional risk factors for postoperative dysphagia.     

Clinical outcomes following surgical management of coexistent cervical stenosis and multiple sclerosis: a cohort-controlled analysis

Background contextThe presentation of myelopathy in patients with the concomitant diagnosis of cervical stenosis (CS) and multiple sclerosis (MS) complicates both diagnosis and treatment because of the similarities of presentation and disease progression. There are only a few published case series that examine this unique patient population.PurposeTo define the demographic features and presenting symptoms of patients with both MS and CS and to investigate the immediate and long-term outcomes of surgery in patients with MS and CS.Study design/settingMatched cohort-controlled retrospective review of 77 surgical patients in the MS group and 77 surgical patients in the control group. Outcome measures were immediate and long-term postoperative neck pain, radiculopathy, and myelopathy; Nurick Disability and modified Japanese Orthopaedic Association scores were collected as well.MethodsRetrospective review was performed for all patients presenting at one institution between January 1996 and July 2011 with coexisting diagnoses of MS and CS who had presenting symptoms of myelopathy and who then underwent cervical decompression surgery. Each study patient was individually matched to a control patient of the same gender and age that did not have MS, but that did have cervical spondylotic myelopathy or myeloradiculopathy. Each control patient underwent the same surgical procedure within the same year.ResultsA total of 154 patients were reviewed, including 77 MS patients and 77 control patients, for an average follow-up of 58 months and 49 months, respectively. Patients in the control group were more likely to have preoperative neck pain (78% vs. 47%; p=.0001) and preoperative radiculopathy (90% vs. 75%; p=.03) than their counterparts in the MS group. Patients in the MS group had a significantly lower rate of postoperative resolution of myelopathic symptoms in both the short-term (39% in the MS group did not improve vs. 23% in the control group; p=.04) and the long-term (44% in the MS group did not improve vs. 19% in the control group; p=.004). Preoperative myelopathy scores were worse for the MS cohort as compared with the control cohort (1.8 vs. 1.2 in the Nurick scale, p<.0001; 13.7 vs. 15.0 in the modified Japanese Orthopaedic Association scale, p=.002). This difference in scores became even greater at the last follow-up visit with Nurick scores of 2.4 versus 0.9 (p<.0001) and modified Japanese Orthopaedic Association scores of 16.3 versus 12.4 (p<.0001) for the MS and control patients, respectively.ConclusionsMyelopathic patients with coexisting MS and CS improve after surgery, although at a lower rate and to a lesser degree than those without MS. Therefore, surgery should be considered for these patients. MS patients should be informed that myelopathy symptoms are less likely to be alleviated completely or may only be alleviated temporarily because of progression of MS and that surgery can help alleviate neck pain and radicular symptoms.     

Surgically treated cervical myelopathy: a functional outcome comparison study between multilevel anterior cervical decompression fusion with instrumentation and posterior laminoplasty

Background contextMultilevel cervical myelopathy can be treated with anterior cervical discectomy and fusion (ACDF) or corpectomy via the anterior approach and laminoplasty via the posterior approach. Till date, there is no proven superior approach.PurposeTo elucidate any potential advantage of one approach over the other with regard to clinical midterm outcomes in this study.Study designA prospective, 2-year follow-up of patients with cervical myelopathy treated with multilevel anterior cervical decompression fusion and plating and posterior laminoplasty.Patient sampleIn total, 116 patients were studied. Sixty-four patients underwent ACDF two levels and above or anterior cervical corpectomy and fusion one level and above. Fifty-two patients underwent posterior cervical surgery (laminoplasty C3–C6 and C3–C7).Outcome measuresSelf-report measures: Japan Orthopedic Association (JOA) score, JOA recovery rate, visual analog scale for neck pain (VASNP), neck disability index (NDI), and American Academy of Orthopaedic Surgeons (AAOS) neurogenic symptom score (AAOS-NSS). Physiologic measures: range of motion (ROM) flexion and extension of neck. Functional measures: short-form 36 (SF-36) score comprising physical functioning, physical role function, bodily pain, general health, vitality, social role function, emotional role function, and mental health scales.MethodsComparison of the JOA scores, JOA recovery rates, NDI scores, SF-36 scores, VASNP, and ROM preoperatively to 2 years. Chi-square and two-sided Student t tests were used to analyze the variables.ResultsPosterior surgery took an hour shorter (p<.05) and had better improvement in JOA scores at early follow-up of 6 months (p=.025). Anterior surgery group had better improvement of NDI scores at early follow-up of 6 months (p=.024) and was associated with less blood loss intraoperatively compared with posterior surgery. There was no statistical difference between the two groups for JOA scores, JOA recovery rates, SF-36 quality-of-life scores, NDI, AAOS-NSS, VAS neck pain, and ROM at 2 years. Complications were higher for anterior surgery group: two hematoma postoperation, one vocal cord paresis, and one new onset C6/C7 dermatome numbness versus one dura leak in posterior surgery group.ConclusionsOur study showed that patients with multilevel disease treated with laminoplasty do well and compare favorably with patients treated with an anterior approach. Notably, posterior surgery was associated with shorter operating time, better improvement in JOA scores at 6 months, and a tendency toward lesser complications. Posterior surgery was not associated with increased neck disability and neck pain at 2 years. Anterior surgery had better NDI improvement at early follow-up. There is a need for a larger study that is prospectively randomized with long-term follow-up before we can confidently advocate one approach over the other in the management of cervical myelopathy.     

Characteristics and outcomes of patients undergoing lumbar spine surgery for axial back pain in the Michigan Spine Surgery Improvement Collaborative

BACKGROUND CONTEXTThe indications for surgical intervention of axial back pain without leg pain for degenerative lumbar disorders have been limited in the literature, as most study designs allow some degree of leg symptoms in the inclusion criteria.PURPOSETo determine the outcome of surgery (decompression only vs. fusion) for pure axial back pain without leg pain.STUDY DESIGN/SETTINGProspectively collected data in the Michigan Spine Surgery Improvement Collaborative (MSSIC).PATIENT SAMPLEPatients with pure axial back pain without leg pain underwent lumbar spine surgery for primary diagnoses of lumbar disc herniation, lumbar stenosis, and isthmic or degenerative spondylolisthesis ≤ grade II.OUTCOME MEASURESMinimally clinically important difference (MCID) for back pain, Numeric Rating Scale of back pain, Patient-Reported Outcomes Measurement Information System Physical Function (PROMIS-PF), MCID of PROMIS-PF, and patient satisfaction on the North American Spine Surgery Patient Satisfaction Index were collected at 90 days, 1 year, and 2 years after surgery.METHODSLog-Poisson generalized estimating equation models were constructed with patient-reported outcomes as the independent variable, reporting adjusted risk ratios (RR_adj).RESULTSOf the 388 patients at 90 days, multi-level versus single level lumbar surgery decreased the likelihood of obtaining a MCID in back pain by 15% (RR_adj=0.85, p=.038). For every one-unit increase in preoperative back pain, the likelihood for a favorable outcome increased by 8% (RR_adj=1.08, p<.001). Of the 326 patients at 1 year, symptom duration > 1 year decreased the likelihood of a MCID in back pain by 16% (RR_adj=0.84, p=.041). The probability of obtaining a MCID in back pain increased by 9% (RR_adj=1.09, p<.001) for every 1-unit increase in baseline back pain score and by 14% for fusions versus decompression alone (RR_adj=1.14, p=.0362). Of the 283 patients at 2 years, the likelihood of obtaining MCID in back pain decreased by 30% for patients with depression (RR_adj=0.70, p<.001) and increased by 8% with every one-unit increase in baseline back pain score (RR_adj=1.08, p<.001).CONCLUSIONSOnly the severity of preoperative back pain was associated with improvement in MCID in back pain at all time points, suggesting that surgery should be considered for selected patients with severe axial pain without leg pain. Fusion surgery versus decompression alone was associated with improved patient-reported outcomes at 1 year only, but not at the other time points.     

Results of the prospective,randomized, controlled multicenter Food and Drug Administration investigational device exemption study of the ProDisc-C total disc replacement versus anterior discectomy and fusion for the treatment of 1-level symptomatic cervical disc disease

Background contextCervical total disc replacement (TDR) is intended to address radicular pain and preserve functional motion between two vertebral bodies in patients with symptomatic cervical disc disease (SCDD).PurposeThe purpose of this trial is to compare the safety and efficacy of cervical TDR, ProDisc-C (Synthes Spine Company, L.P., West Chester, PA), to anterior cervical discectomy and fusion (ACDF) surgery for the treatment of one-level SCDD between C3 and C7.Study design/settingThe study was conducted at 13 sites. A noninferiority design with a 1:1 randomization was used.Patient sampleTwo hundred nine patients were randomized and treated (106 ACDF; 103 ProDisc-C).Outcome measuresVisual analog scale (VAS) pain and intensity (neck and arm), VAS satisfaction, neck disability index (NDI), neurological exam, device success, adverse event occurrence, and short form-36 (SF-36) standardized questionnaires.MethodsA prospective, randomized, controlled clinical trial was performed. Patients were enrolled and treated in accordance with the US Food and Drug Administration (FDA)–approved protocol. Patients were assessed pre– and postoperatively at six weeks, 3, 6, 12, 18, and 24 months.ResultsDemographics were similar between the two patient groups (ProDisc-C: 42.1±8.4 years, 44.7% males; Fusion: 43.5 ± 7.1 years, 46.2% males). The most commonly treated level was C5–C6 (ProDisc-C: 56.3%; Fusion=57.5%). NDI and SF-36 scores were significantly less compared with presurgery scores at all follow-up visits for both the treatment groups (p<.0001). VAS neck pain intensity and frequency as well as VAS arm pain intensity and frequency were statistically lower at all follow-up timepoints compared with preoperative levels (p<.0001) but were not different between treatments. Neurologic success (improvement or maintenance) was achieved at 24 months in 90.9% of ProDisc-C and 88.0% of Fusion patients (p=.638). Results show that at 24 months postoperatively, 84.4% of ProDisc-C patients achieved a more than or equal to 4° of motion or maintained motion relative to preoperative baseline at the operated level. There was a statistically significant difference in the number of secondary surgeries with 8.5% of Fusion patients needing a re-operation, revision, or supplemental fixation within the 24 month postoperative period compared with 1.8% of ProDisc-C patients (p=.033). At 24 months, there was a statistically significant difference in medication usage with 89.9% of ProDisc-C patients not on strong narcotics or muscle relaxants, compared with 81.5% of Fusion patients.ConclusionsThe results of this clinical trial demonstrate that ProDisc-C is a safe and effective surgical treatment for patients with disabling cervical radiculopathy because of single-level disease. By all primary and secondary measures evaluated, clinical outcomes after ProDisc-C implantation were either equivalent or superior to those same clinical outcomes after Fusion.     

Influence of the mental health status on a new measure of objective functional impairment in lumbar degenerative disc disease

Background Context

The Timed Up and Go (TUG) test has recently been proposed as a simple and standardized measure for objective functional impairment (OFI) in patients with lumbar degenerative disc disease (DDD).

Determination of minimum clinically important difference (MCID) in pain,disability, and quality of life after revision fusion for symptomatic pseudoarthrosis

Background contextSpinal surgical outcome studies rely on patient reported outcome (PRO) measurements to assess the effect of treatment. A shortcoming of these questionnaires is that the extent of improvement in their numerical scores lacks a direct clinical meaning. As a result, the concept of minimum clinically important difference (MCID) has been used to measure the critical threshold needed to achieve clinically relevant treatment effectiveness. Post hoc anchor-based MCID methods have not been applied to the surgical treatment for pseudoarthrosis.PurposeTo determine the most appropriate MCID values for visual analog scale (VAS), Oswestry Disability Index (ODI), Short Form (SF)-12 physical component score (PCS), and European Quality of Life 5-Dimensions (EQ-5D) in patients undergoing revision lumbar arthrodesis for symptomatic pseudoarthrosis.Study design/ settingRetrospective cohort study.MethodsIn 47 patients undergoing revision fusion for pseudoarthrosis-associated back pain, PRO measures of back pain (BP-VAS), ODI, physical quality of life (SF-12 PCS), and general health utility (EQ-5D) were assessed preoperatively and 2 years postoperatively. Four subjective post hoc anchor-based MCID calculation methods were used to calculate MCID (average change; minimum detectable change; change difference; and receiver operating characteristic curve analysis) for two separate anchors (health transition index (HTI) of SF-36 and satisfaction index).ResultsAll patients were available for a 2-year PRO assessment. Two years after surgery, a significant improvement was observed for all PROs; Mean change score: BP-VAS (2.3±2.6; p<.001), ODI (8.6%±13.2%; p<.001), SF-12 PCS (4.0±6.1; p=.01), and EQ-5D (0.18±0.19; p<.001). The four MCID calculation methods generated a wide range of MCID values for each of the PROs (BP-VAS: 2.0–3.2; ODI: 4.0%–16.6%; SF-12 PCS: 3.2–6.1; and EQ-5D: 0.14–0.24). There was no difference in response between anchors for any patient, suggesting that HTI and satisfaction anchors are equivalent in this patient population. The wide variations in calculated MCID values between methods precluded any ability to reliably determine what the true value is for meaningful change in this disease state.ConclusionsUsing subjective post hoc anchor-based methods of MCID calculation, MCID after revision fusion for pseudoarthrosis varies by as much as 400% per PRO based on the calculation technique. MCID was suggested to be as low as 2 points for ODI and 3 points for SF-12. These wide variations and low values of MCID question the face validity of such calculation techniques, especially when applied to heterogeneous disease and patient groups with a multitude of psychosocial confounders such as failed back syndromes. The variability of MCID thresholds observed in our study of patients undergoing revision lumbar fusion for pseudoarthrosis raises further questions to whether ante hoc or Delphi methods may be a more valid and consistent technique to define clinically meaningful, patient-centered changes in PRO measurements.